Very interesting perspective on the approach to combat spam. While I agree with the difficulty of focusing on this versus trying to get more on board the platform, I think they went halfway as the new Resource Credit system will replace the Steemit Inc delegation of SP to create accounts. So I think they are trying to do both and while it has been a bumpy road, some early indications show that it could work as RC are now charging at higher rates. While time will tell if this was a success, I could say that at least this approach will be able to provide the necessary data over time to adjust the system to focus on either of the objectives you mention; which is a flexibility not really available before.